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1.
Dynamic-mechanical analysis and SEM morphology of wood flour/polypropylene composites 总被引：1，自引：0，他引：1
GUO Chui-gen SONG Yong-ming WANG Qing-wen SHEN Chang-sheng 《林业研究》2006,17(4):315-318
Introduction It is well known that over the past few decades, polymers have replaced many conventional materials, such as metal and wood in many applications. This is due to the advantages of polymers over conventional materials (Maurizio et al. 1998; Adr… 相似文献
2.
Wenjie Dang Yongming Song Qingwen Wang Weihong Wang 《Frontiers of Forestry in China》2008,3(2):243-247
To improve the interfacial compatibility between wood fibers and polypropylene and the toughness of wood-fiber/polypropylene
composites, maleic anhydride grafted polypropylene (PP-g-MAH) and maleic anhydride grafted styrene-ethylene-butadiene-styrene
copolymers (SEBS-g-MAH) were used as modifiers. Mechanical properties of wood-fiber/polypropylene (WF/PP) composites were
improved when PP-g-MAH or SEBS-g-MAH was added. When either of these copolymers was added, the composites had better interfacial
compatibility than the unmodified composite. This was verified by scanning electron microscope (SEM) observations and dynamic
mechanical analysis (DMA). The mechanical properties of the composites were significantly improved because of the good interfacial
bonding between wood fibers and polypropylene when PP-g-MAH and SEBS-g-MAH were added.
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Translated from Journal of Beijing Forestry University, 2007, 29(2): 133–137 [译自: 北京林业大学学报] 相似文献
3.
ABSTRACTIn this study, wood flour/polypropylene (WF/PP) composites were prepared by incorporating 2?wt% carbon materials with different morphologies, including carbon black (CB), graphite (G), and multi-walled carbon nanotubes (CNTs). WF/PP composite without any additives was included as a reference. All composites were placed in the accelerated UV weathering tester for a total of 960 h. The physical and mechanical properties of composites were compared. The changes in surface morphology and surface chemistry were characterized by SEM AFM, and ATR-FTIR. The results showed that: (1) the addition of CNTs improved both flexural and impact properties of composites; (2) composites containing CNTs exhibited better color stability and less severe surface cracking during weathering; and (3) ATR-FTIR results revealed that all the additives alleviated surface photo-oxidation of composites due to their UV-screening effect. Overall, due to the improved interfacial bonding between WF and PP, CNTs were more effective in protecting wood–plastic composites from photodegradation. 相似文献
4.
Wood flour (WF) and polypropylene (PP) composites (WF/PP) were compatibilized by m-isopropenyl-α,α-dimethylbenzyl isocyanate grafted polypropylene (m-TMI-g-PP). The effect of wood flour, m-TMI-g-PP contents on the rheology, dynamic mechanical analysis (DMA), mechanical properties, as well as the morphology of the composites were investigated and discussed. Rheology, DMA results showed that m-TMI-g-PP was an effective compatibilizer for WF/PP composites. The shear modulus (G′) and complex viscosity (η*) of the composites were increased, which implied that the composites probably withstood pronounced shear forces, resulting from strong adhesion at the interface between the matrix PP and WF. The mechanical test indicated that the tensile strength and the flexural strength of the composites were improved with increasing content of m-TMI-g-PP. From the properties tests, the optimum loading of WF in WF/m-TMI-g-PP/PP was found to be 40%, and the optimum loading of m-TMI-g-PP was 6%. Property enhancement is attributed to improved wetting and interactions between the PP matrix and WF, which is supported by scanning electron microscopy analysis. 相似文献
5.
GUO Chui-gen WANG Qing-wen MOE Key Laboratory of Bio-based Material Science Technology Northeast Forestry University Harbin P. R. China 《林业研究》2007,(3)
马来酸酐接枝苯乙烯-乙烯-丁烯-苯乙烯(MA-SEBS)用作聚丙烯/木纤维复合体系的界面相容剂及冲击改性剂,来提高其界面粘接及冲击强度。研究了MA-SEBS含量对PP/WF复合材料冲击断裂行为的影响,当MA-SEBS含量达到8%时,冲击性能达到了最大值,进一步增加到10%并未提高其断裂韧性,但动态热机械分析(DMA)表明复合材料刚性的提高,这归因于PP/WF界面的改善,当MA-SEBS超过8%,聚丙烯与木纤维分子间的相互作用增强。扫描电子显微镜(SEM)分析了样品的断裂表面,表明木纤维与聚丙烯表面强烈的界面粘结。图5表1参11。 相似文献
6.
In this paper, the influence of melamine polyphosphate (MPP) and aluminum hypophosphite (AHP) on mechanical properties, flame retardancy and thermal degradation of high-density polyethylene/wood flour composites (HDPE/WF) was investigated. The synergistic effect of MPP and AHP was investigated. Polyethylene grafted with maleic anhydride (PE-g-MAH) was used as coupling agent. The experimental data demonstrated that the HDPE/WF composites with 35 wt% MPP/AHP (3:2) could achieve a LOI value of 29.6 % and UL-94 V-0 rating. In addition, the cone value also revealed that the heat release rate and the smoke production rate were clearly reduced. SEM results showed that the synergistic system (MPP/AHP = 3:2) could form a dense and thick char layer and good adhesion between wood flour and HDPE matrix, which prevented the transfer of heat flux and fuel gases. Incorporation of MPP and AHP improved the thermal stability of HDPE/wood flour as observed from the thermogravimetric analysis results and also enhanced the thermal resistance of char layer at high temperature based on scanning electron microscopy observation. 相似文献
7.
Fauzi Febrianto Mariko Yoshioka Yuko Nagai Makoto Mihara Nobuo Shiraishi 《Journal of Wood Science》1999,45(1):38-45
The modification oftrans-1,4-isoprene rubber (TIR) with maleic anhydride (MAH) was conducted in a kneader at 150°C, 30–70 rpm, for 10 min without using peroxide. The resultant MAH-modified TIR (MTIR) was then evaluated as a compatibilizer for TIR-wood flour (WF) composites. A control composite composed of TIR and WF only was also prepared. The presence of WF in the TIR-WF composite worsened the tensile and some physical properties. The addition of 5% MTIR as a compatibilizer to the whole composite improved the mechanical and the physical properties and increased the flow temperature and the melt viscosity. The improved composite had a 2.5 times increase in tensile strength and absorbed considerably less water than did the control composite. The SEM micrograph proved that interaction and adhesion between TIR and WF could be improved by the MTIR compatibilizer. The composites of TIR-MTIR-WF melts were of pseudoplastic nature, and their flows obeyed the Ostwald de Waele power law equation. 相似文献
8.
MA-SEBS as compatibilizer and impact modifier was incorporated into Polypropylene/Wood Fiber （PP/WF） to enhance interface adhesion and impact strength of the composite. The effect of MA-SEBS content on the impact fracture behavior of PP/WF composites was studied. The impact properties of composites with 8% MA-SEBS reached the maximum value. And further increasing of MA-SEBS content to 10% did not improve the fracture toughness, but improved the stiffness of composites by DMA analysis. This was attributed to the improved PP/WF adhesion. As the MA-SEBS content is more than 8%, the molecule interaction of PP and WF was expected to much stronger than lower MA-SEBS. Scanning electron microscopy （SEM） was performed to analyze the impact fracture surface and showed a stronger affinity for the wood surfaces. 相似文献
9.
Masahiro Takatani Kohei Ikeda Kei Sakamoto Tadashi Okamoto 《Journal of Wood Science》2008,54(1):54-61
One of the important issues relevant to wood/plastic composite molding is the compatibility between hydrophilic wood and hydrophobic
plastic. Polyolefins modified with maleic anhydride, which have been frequently used for wood and polyolefin composites, are
not effective for poly(lactic acid) composites. Because compounds with both hydrophilic and hydrophobic groups are potential
compatibilizers, cellulose esters of several carboxylic acids, RCOO-cellulose (R = CH3, C2H5, C3H7, C4H9, C5H11, C11H23), were synthesized and their effects as compatibilizers of wood/poly(lactic acid) composites (WPLC) were examined in this
study. The mechanical properties of WPLC were improved with a small amount of added cellulose esters, especially cellulose
butyrate or cellulose valerate. The relevant effect of added cellulose esters on the thermal properties of wood/PLA composite
was analyzed by measuring dynamic viscoelasticity.
Part of this report was presented at the 56th Annual Meeting of Japan Wood Research Society, Akita, August 2006 and the 9th
International Conference on Frontiers of Polymers and Advanced Materials, Cracow, Poland, July, 2007 相似文献
10.
Wood polymer nanocomposites (WPNC) based on nano-SiO2 were prepared by impregnation of styrene acrylonitrile copolymer (SAN), SiO2 nanoparticles modified with γ-trimethoxy silyl propyl methacrylate (MSMA), and nanoclay into wood. The structure of modified SiO2 nanoparticles and WPNC was characterized by Fourier transform infrared spectroscopy (FTIR). XRD analysis showed the delaminated structure of SAN/SiO2/clay-treated wood composites. The synergistic effect of nano-SiO2 and nanoclay was investigated. Thermal stability of SiO2 nanoparticles decreased after modification, while that of wood treated with SAN, SiO2, and nanoclay improved. Morphological characteristics were examined by scanning electron microscopy (SEM). Mechanical properties, water uptake (%), dimensional stability, hardness, and flammability were found to improve due to incorporation of SiO2 and nanoclay into wood polymer composites. Maximum improvement in properties was observed in the wood polymer composites containing SiO2 and nanoclay at the ratio of 1:1. 相似文献
11.
木纤维PP/PE共混物复合材料的流变和力学性能(英文) 总被引：2，自引：0，他引：2
For evaluation of the rheological and mechanical properties of highly filled wood plastic composites （WPCs）, polypropylene/polyethylene （PP/PE） blends were grafted with maleic anhydride （MAH） to enhance the interfacial adhesion between wood fiber and matrix. WPCs were prepared from wood fiber up to 60 wt.% and modified PP/PE was blended by extrusion. The rheological properties were studied by using dynamic measurement. According to the strain sweep test, the linear viscoelastic region of composites in the melt was determined. The result showed that the storage modulus was independent of the strain at low strain region （〈0.1%）. The frequency sweep resuits indicated that all composites exhibited shear thinning behavior, and both the storage modulus and complex viscosity of MAH modified composites were decreased comparing to those unmodified. Flexural properties and impact strength of the prepared WPCs were measured according to the relevant standard specifications. The flexural and impact strength of the manufactured composites significantly increased and reached a maximum when MAH dosage was 1.0 wt%, whereas the flexural modulus after an initial decreased, also increased with MAH dosage. The increase in mechanical properties indicated that the presence of anhydride groups enhanced the interracial adhesion between wood fiber and PP/PE blends. 相似文献
12.
F. Febrianto M. Yoshioka Y. Nagai M. Mihara N. Shiraishi 《Wood Science and Technology》2001,35(4):297-310
The occurrence of grafting between WF and MTIR through esterification, the processing conditions for production of the composites,
and the effect of MAH concentration on some physical and mechanical properties as well as the biodegradability of the composites
have been studied. The FTIR measurement demonstrated that grafting through esterification had been attained between OH-groups
of WF and acid anhydride groups of MTIR during kneading. The optimum kneading conditions for preparing the composites were
120 °C, 30 ∼ 90 rpm for 10 min. The tensile properties of the composites with WF based filler are greater than those with
CS (corn starch) based filler. Addition of 10% of MTIR•10 and 8% MAH prepared using the two-step and one-step process, respectively to the TIR-WF composites gave the best result of tensile properties. The presence of MAH in the TIR-WF
composites also improved the dimensional stabilization of the resulting composites. The tensile strengh of the composites
prepared using the one-step process was about 90% of the composite prepared using the two-step process. The composites of TIR-WF with MTIR compatibilizer had slightly less resistance against subterranean termite (C. formasanus), brown-rot fungus (T. palustris), and white-rot fungus (C. versicolor) and slightly more resistance against bacteria (Bacillus sp.), within the experimental conditioned adopted.
Received 8 February 1999 相似文献
13.
Flax fiber(FF) was used to reinforce wood flour/high density polyethylene composites(WF/PE).WF/PE particles were uniformly mixed with FF via high-speed mixing and then extruded with a single screw extruder to prepare FF reinforced WF/PE composites(FF/WF/PE).Mechanical testing,dynamic mechanical analysis,scanning electron microscopy(SEM),creep measurement and Torque rheology were used to characterize the resulting composites.The results indicate that the mechanical performance of the composites could be remarkably improved by adding a limited amount of FF.The flexural strength and modulus increased by 14.6 and 51.4%,respectively(FF content of 9 wt%),while the unnotched impact strength could be increased by 26.5%(FF content of12 wt%).The creep resistance and toughness of thecomposite was markedly improved without changing the plastic content of the composite material. 相似文献
14.
改善木塑复合材料界面相容性的途径 总被引：35，自引：0，他引：35
本文介绍了国内外在改善木塑复合材料的界面复合性能方面所采用的最新研究方法和取得的研究成果。几乎所有的研究都表明:在木塑复合过程中木材与热塑性高分子聚合物之间界面的粘合性能和作为填充物的木材在热塑性高分子聚合物基材中的分散性是影响木塑复合材料的物理、力学性能的主要因素。同时对如何改进木塑复合材料界面相容性的研究方法进行了系统的介绍。 相似文献
15.
Preparation of acetylated wood meal and polypropylene composites II: mechanical properties and dimensional stability of the composites 总被引：2，自引：0，他引：2
Acetylated wood meals of Sugi (Cryptomeria japonica D.Don) wood were prepared by mechanochemical processing using a high-speed vibration rod mill. Weight percent gain (WPG) of the acetylated wood meals ranged from 7.0 to 35.5 %. Wood–plastic composites (WPCs) containing 50 % acetylated woods were produced by an injection molding technique. The polymer matrix used was polypropylene homopolymer. Maleic anhydride-grafted polypropylene (MAPP) was also used as a compatibilizing agent. The mechanical properties of WPCs in bending and tensile tests were independent of WPG of acetylated wood meals, and the test values for WPCs containing acetylated wood meals were lower than that of unmodified wood meal. The use of MAPP increased bending and tensile strength, but no effect on bending modulus was found. An increase in WPG significantly decreased water absorbability and thickness swelling of WPCs as measured by dimensional stability tests. These results demonstrated that mechanochemical processing is a promising technique for preparing WPC material with improved dimensional stability. The future challenge is to inhibit the decreases in mechanical properties of WPCs containing acetylated wood meals. 相似文献
16.
《Wood material science & engineering》2013,8(6):381-391
ABSTRACTSafer environmental requirements have resulted in significant interest in natural polymer-based materials to increase sustainability. In this perspective, wood polymer nanocomposites are of particular interest. Wood polymer nanocomposites were prepared from modified soybean oil, wood flour and cetyl trimethylammonium bromide modified bentonite using the compression-molding technique. Fourier transform infrared spectroscopy and X-ray diffractometric studies were used to confirm the successful modification of bentonite. Incorporation of 3?wt% of bentonite in the composites produced significant improvement in properties compared to those of 1 and 5?wt%. Furthermore, in comparison to the unfilled nanocomposites, nanoclay-filled ones showed an enhanced UV resistance property as judged by lower weight loss and carbonyl index. The decrease in mechanical properties of UV-exposed unfilled composites was more significant compared to those of nanoclay-filled composites. Scanning electron microscope and transmission electron microscope were used to study the surface morphology and distribution of the bentonite into the composites. In addition, with the incorporation of bentonite, significant increase in thermal, mechanical and flame-retarding properties was observed. 相似文献
17.
18.
To improve interfacial adhesion between wood veneer and high-density polyethylene (HDPE) film, wood veneer was thermally modified in an oven or chemically modified by vinyltrimethoxysilane. The wood veneers were used to prepare plastic-bonded wood composites (PBWC) in a flat-press process using HDPE films as adhesives. The results showed that both modifications reduced veneer hydrophilicity and led to enhancement in shear strength, wood failure, and water resistance of the resulting PBWC. The thermal treatment significantly decreased the storage modulus close to 130 °C (the melting temperature of plastic). Thermal-treated wood veneer maintains mechanical interlocking for bonding and veneer strength which then declined under thermal treatment due to hemicellulose degradation and cellulose de-polymerization. In the silane-treated PBWC, enhanced interlocking and a stronger bonding structure resulted from the reaction between the silane-treated veneer and HDPE. This strong bonding structure allowed thermal stability improvement demonstrated by high modulus and low tanδ values. However, the strength of silane-treated PBWC was still much lower than thermosetting resin-bonded composites at higher temperatures due to the melting behavior of thermoplastic polymer, precluding its use in certain applications. 相似文献
19.
Kevlar fiber (KF) is a synthesized product with strong mechanical properties. We used KF as a reinforcement to improve the mechanical properties of wood-flour/polypropylene (WF/PP) composites. KF was pretreated with NaOH to improve its compatibility with the thermoplastic matrix. Maleated polypropylene (MAPP) was used as a coupling agent to improve the interfacial adhesion between KF, WF, and PP. Incorporation of KF improved the mechanical properties of WF/PP composites. Treatment of KF with NaOH resulted in further improvement in mechanical strength. Addition of 3% MAPP and 2% hydrolyzed KF (HKF) led to an increment of 93.8% in unnotched impact strength, 17.7% in notched impact strength, 86.8% in flexure strength, 50.8% in flexure modulus, and 94.1% in tensile strength compared to traditional WF/PP composites. Scanning electron microscopy of the cryoractured section of WF/PP showed that the HKF surface was rougher than the virgin KF, and the KF was randomly distributed in the composites, which might cause a mechanical interlocking between KF and polypropylene molecules in the composites. 相似文献
20.
In order to improve wood properties of triploid clones of Populus tomentosa, urea-formaldehyde (UF) resin was compounded with nano-SiO2, coupling agents and flame retardants in different ways to prepare five kinds of modifiers. The poplar wood samples were
impregnated with the modifiers and heated to prepare UF-SiO2-wood composites. The antiswelling efficiency, resistance of water absorption, oxygen index and hardness of the composites
were measured. Results show that all of the modifiers reduced water absorption of poplar wood and enhanced flame resistance
and hardness. Nano-SiO2 showed a marked effect in improving the hardness of wood. In addition, all of the modifiers, except UF-C-SiO2-polymer, improved the dimensional stability of poplar wood. The UF resin and nano-SiO2 compound improved general properties of poplar wood.
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Translated from Journal of Beijing Forestry University, 2006, 28(2): 123–128 [译自: 北京林业大学学报] 相似文献